Helical single knife type bread slicer



Feiao l, 1938. T. JENSEN ET AL HELICAL SINGLE KNIFI? TYPE BREAD SLICER 5 Sheets-Sheet 1 Filed Feb. 27 1954 wwN mm Feb, 1, 1938. T. JENSEN ET AL 2,107,002

HELICAL SINGLE KNIFE TYPE BREAD SLICER Filed Feb. 27 1954 3 Sheets-Sheet 2 Patented el). 1 1938 UNITED STATES amiss?! PATENT OFFHCE HELICAL SINGLE KNEFE TYPE BREAD SLICER of New Jersey Application February 27, 1934, Serial No. 713,174

9 Claims.

This invention relates to slicing machines, more particularly to bread slicing machines, its main object being the production of a bread slicing machine operating to slice a loaf while it is being continuously advanced' A further object of the invention is to provide a rotary knife which has a volute cutting edge and is distorted into a helical form every portion of which lies on radii perpendicular to the shaft on which the knife is mounted, whereby the loaf will be sliced as it is moved under the knife. Still another object is to firmly support the loaf during the slicing thereof by steadying the loaf conveyor during its travel under the knife and backing up the loaf against the thrust of the knife. With these and other objects not specifically mentioned in view, the invention consists in certain constructions and combinations hereinafter fully described and then specifically set forth in the appended claims.

In the accompanying drawings which form a part of this specification and in which like characters of reference indicate the same or like parts:

Fig. l is a side elevation of the bread slicing machine showing the infeed, slicing and transfer mechanisms;

Fig. 2 is a detail sectional view of the slicer mechanism taken on line 22 of Fig. 1;

Fig. 3 is a partial top view of the same'show ing the means for guiding and holding the loaf while being sliced;

Fig. 4 is a side elevation of the same; and

Fig. 5 is a detail end view of the runway.

In carrying the invention into effect there is provided a helical knife having a volute cutting edge, means for rotating said knife, and mechanism for advancing a loaf continuously across the path of said knife. In the best constructions contemplated said means includes a shaft, 21 flange fast on said shaft and having a helical face lying on radii perpendicular to the axis of the said shaft, and a clamp plate secured to' said flange, and the knife having acentral aperture in which the hub of the flange is fitted, the knife being clamped against the helical face of said flange by said plate and thus distorted into helical form. The mechanism for continuously advancing the loaves across the path of the knife may include in the best constructions contemplated a pair of traveling endless chains each provided with a plurality of spaced flights rigidly connected thereto, each flight on one chain being disposed to clamp a loaf against an adjacent flight on the other chain, a pair of stationary bars parallel to said chains, and provided with a longitudinal track, and series of rollers rigidly connected to said flights and arranged to enter said tracks and bear against the sides of said bars to steady the flights while they are advancing a loaf across the path of the'knife. These various means and parts may be widely varied in construction within the scope of the claims for the particular machine selected to illustrate the invention is but one of many possible concrete em.- bodiments of the same. The invention, therefore, it not to be restricted to the specific construction shown and described.

Referring to Fig. l'of the drawings, the infeed chute it is suitably supported in inclined position by floor posts (not shown), the chute I0 having relatively adjustable side walls ll. At its lower end, the chute l0 delivers the loaves onto a table I2 supported on the frames l3, l4, and E5. The flights l6 and I! attached to chains l8 and i9, respectively, enter the space between the table l2 and plate (Figs. 2 and 3) to advance the loaves. Table I2 is providedwith an adjustable sidewall 2I supported by angle 22 to bear against one side of the loaf as it is advanced along the table.

On the shaft. of motor 23 is mounted a pulley 24 which by means of a belt 25 drives a pulley 26 on knife shaft 21. Shaft 27 carries a Worm 28 meshing with a worm wheel 29 mounted ona vertical shaft 30. The shaft 30 by means of a gear (not shown) drives a shaft 3| which in turn, through a suitable gear transmission (not shown) drives a shaft 32.

frames 14 and l5.

p The gear transmission 3 is enclosed in a housing 33 supported by the One end of the shaft 32 carries a bevel gear I 34 which meshes with a gear 35 mounted on shaft 36. A bevel gear 3'! mounted on the other end of shaft 35 meshes with a gear 38 (see Fig. 2). At the other end of shaft 32 there .is mounted a bevel gear 39 (see Fig. 1) which drives a gear 40 carried by a shaft 4| supported in bearings'42 attached to the frame 43. The shaft 4! carries a pair of sprockets 44 and 45 which drive I the conveyor chains !8 and 19 respectively. The

The shaft 56 carries a sprocket H which drives a chain 62 running over a sprocket 63 fastened to a shaft 64, the same being mounted in brackets 65 and 66. A second sprocket 61 carried by shaft 64 drives a transfer chain 68 running over an idler sprocket'69 carried by shaft I0, the shaft being supported in brackets 65 and. 66. The rear bracket 66 carries a guide bracket II provided with a cam surface I2, a track I3 and a curved guide surface 14. The conveyor chain 68 has a set of spaced blocks I5 which carry pivotally mounted arms 16, the arms I6 being equipped with rollers I1. The projecting ends I8 of the arms I6 support the pusher plates 19. The rollers" of the hanging arms I6 encounter the cam surface I2, and gradually lift the same from a horizontal to a vertical position. The continued movement of the chain brings the rollers 11 into engagement with the track I3 thus assuring a vertical position of the pusher I9 while transferring the loaf along table I2.

Referring now to Figs. 3 and 4, the table I2 is provided with a transverse slot 80, in which is fitted a stud 8| carrying a bracket 82. The bracket 82 supports a stud 83 (see Fig. 4) on which is loosely mounted an arm 84 having a lug '85 attached to the yieldingly mounted guide 86 aligned with wall 2| A torsion spring 81 mounted on stud 83 has two extending ends, one of which bears against a pin 88 in arm 84 and the other against a pin 89 fastened in an adjustably mounted cap 90 on stud 83. The arm 84 is also provided with a lug 9I which engages a stop pin 92 mounted in the bracket 82. A lug 93 which is part of bracket 82 supports the adjacent end of side wall 2|.

The frame I5 supports a bracket 94 carrying guide bars 95 which extend to the infeed chute I0, and have a slotted bar 96 attached thereto (see Figs. 3 and 4). On stud 9I engaging in slot 98 of bar 96 is pivoted a weighted arm 99 carrying a pin I00 engaging in a yoke IOI of a block I02 mounted on stud 91.

The bracket 94 also supports a grooved ledger plate I03 (see Fig. 4). The bevel gear 38, which revolves loosely on a stud I04 carried by a bracket I05 (see Fig. 2), has an annular recess I06 which receives a shouldered portion I0I' of the cage base I08. The cage base I08 has a plurality of spaced vertical slots in which are fastened the upright strips I09 constituting what may be termeda cage. The inclined ridges or fingers separating the grooves in the ledger plate press into the side of the loaf and hold it down firmly on the table I2.

Between the flange IIO, which is fast to the shaft 2I,'and a clamp plate III is held a knife II2 having a serrated volute cutting edge and a central aperture fitted on the hub of flange I I0. The flange II 0 has a helical face lying on radii perpendicular to the axis of the shaft 21 (Fig. 3) I I3 the pitch or lead of which corresponds to the thickness of slice required. The knife H2 and clamp plate III are split so that they may be readily distorted into helical form and seat properly on the helical face of the flange when the screws securing the clamp plate (Fig. 3) to the flange are tightened.

The frame I5 also supports two'brackets H4 and H5 (see Fig. 3) in which are fixed the stationary guide rods H6 and H1. An adjustable slide II8 mounted on the rods H6 and I IT has a projecting member II9, the end of member II9 having an upwardly extending lug I20 to which is fastened a guide plate I2I aligned with guide 86. A knob I22 is provided on the threaded spindle I23 for turning the same to adjust the slide Il8 with guide plate I2I.

A bracket I24 clamped to tie bars 5I and 52 supports rods I25 and I26 (Fig. 3), and on the rods is mounted an adjustable bracket I2I provided with a wide platform I28 supporting three rods I29, one end of the rods carrying a gap plate I30 (see Figs. 3 and 4). Bracket I21 is also provided with an integral narrow platform supporting a bar I3I which at one end carries a gap plate I32. A stud I33 projecting from the slice guide I34 acts as a support for the bar I3I. The slice guide I34 also carries a set of guide bars I35.

The flights I6 (Figs. 1 and 2) are fastened to spaced carriages I36 each secured to the ends of one of the links of chain I8 and supporting rollers I3I which engage in the track I38 of the front bar I39 during the travel of chain I8. The bar I39 is placed in the space between the conveyor drive sprockets 44 and 45 and the idler sprockets 51 and 58. The carriages I36 also support a double set of rollers I40 which ride on the sides of the bar I39. In this manner the flights I6 are firmly held against the loaf while conveying the loaf past the slicing knife H2. The flights I I are attached to carriages I36 mounted in the same manner on chain I9, and are guided by means of rollers on the carriages entering a track in rear bar I4I similar to that of bar I39, whereby each flight I1 is rigidly held in upright position to clamp a loaf against the adjacent. flight I6 While the latter advances the loaf along the table I2.

The shaft 32 (Fig. 1) also carries agear I42 meshing with a gear I 43 on shaft I44, one end of shaft I44 being supported in a cap I45 fastened to the bracket I24 and its other end being supported in a bearing of the frame 43. A sprocket I46 attached to the end of shaft I44, through a chain I 4! running over sprocket I40, imparts motion to the transfer shaft I 49. An arm I50 attached to shaft I49, has a roller I5I engaging in the track I52 of a stationary drum cam I53. A set of arms I54 fixed to shaft I49 support a pusher plate I55 which has hinged end pieces I56 yieldingly held in alignment with the pusher plate by torsion springs (not shown) the end pieces being swung back on their hinges whenever any one of the flights I6I1 obstructs their travel. The sprocketl48 which is slidably mounted on a key 151 in shaft I49 is held against axial movement by means of a plug I58 which engages in a circumferential groove provided in the hub of sprocket I48. It maybe noted that a very slight disalignment of the flights I6--II with the 'end faces of the end'pieces I56 is sufficient to obstruct the travel of the latter, since the spaces between the same and the inner faces of the flights must be very narrow in order to eject the end slices with the rest of the sliced loaf.

The operation of the machine is as follows: The loaves L to be sliced are placed in the inclined chute I0, the lowermost loaf on reaching the table I2 stopping against the side wall 2|. In this position the loaf lies directly in the path of one of the pushers I9 which conveys the loaf along table I2. While the loaf is being advanced bythe pusher I9 one of the flights II arrives in front of the loaf and travels along idle until the rear roller 11 attached to the pusher arm I6 leaves the track I3 and follows the rounded guide surface I4. In so doing the pusher 19 :is gradually lifted from the loaf while the rear flight I6 travels around the sprocket 51 and assumes an upright position in which it engages the loaf. In this manner the loaves are clamped between the front and rear flights of the conveyor and are advanced between the guide 86 and guide bars towards the slicing unit.

During its travel through the slicing position the loaf is held down on the table 1-2 and plate 29 by the weighted top tensionarm 99, and resiliently held against the guide 86 and the table by the fingers formed by the grooves I59 in the ledger plate I 03. The knife I l 2 cuts down through the loaf along the inclined edge I60 of the ledger plate I03 while the loaf -is being forwarded, the rim of the knife passing through the gap beyond the-end of table I2 and plate 26 into one of the spaces between-the upright strips I09 of the cage while cutting through the bottom of the loaf. The speed of rotation of the-cage and knife is so timed that the leading end of the knife edge near the split will enter the next space in the cage after starting the next cut in the topof the loaf. The upright strips I09 serve to back-up or hold the unsliced portion of the loaf beyond the ledger plate I03 while the same is being, out. By this means the leaves are sliced while continuously advancing.

In their further travel the sliced loaves are conveyed across the gap plates I30 and I32 over the runway-consisting'of 'the rods I29 and the bar I 3|, and between the side guide I2I and guide bars I35. The continued advance of the conveyor brings the sliced loaf S to its transfer position where'the pusher I55 follows the advancing loaf and at thesame time gradually moves toward the loaf and ejects it from between the flights I6 and I1. The loaf is then propelled between side guides I6I, which lead to the wrapping machine, by the ejection of the following loaves from the conveyor.

The knife shaft 21 is mounted in hangers I62 which are part of the Worm housing I 63. A cover I64 which closes the top of the housing I63 is provided with a boss I65 in which is threaded an adjusting screw I66 having a knob I61 threaded thereon. The knob- I61 is seated against a pad on the motor carrier plate I68 attached to the frames I4 and I 5. The base of the hangers I62 is provided with elongated slots I69 receiving screws I10 which fasten the same to the frames I4 and I5. It will be readily seen that by loosening the screw I10 and turning the knob I61 the position of the knife can be raised or lowered. However, it is desirable that in all adjusted positions of the knife that the axis of the shaft 21 on which it is mounted be inclined sufliciently, as shown in the drawings, to cause the cutting edge of the knife to move through a path substantially perpendicular to the axis of the loaves.

The feet of motor 23 are equipped with gibs "I mounted on slide bars I 12 which are fastened to the plate I68. A cross bar I13 spanned across the rear gibs has a tapped bore into which is threaded an adjusting screw I14 having a knob I15 which provides means for adjusting the motor to regulate the tension of the belt 25.

When a different thickness of slice is desired, another knife flange and cage are substituted; and the speed of the conveyor must also be changed in accordance with the thickness of the slice, as the thinner the slice the slower must be the speed of the conveyor. A shift handle I86 operates a yoke (not shown) which changes the gear ratio of the transmission, which is of a Well known type and-enclosed in housing 33. A plug I81 attached to :handle I86 engages in indexing holes I88 located in a cover I89 of the housing 35, said holes being marked for the thickness of slice desired.

What is claimed is:

1. In a bread slicing machine, the combination with 'a helical knife, :01 means for rotating said knife, a "table beneath said knife, mechanism for continuously advancing a loaf length-.

wise of said table and across the path of said knife, a guide :on the table arranged to' bear against one side of the advancingloaf, and a stationary ledger platearranged to engage the other side of said loaf and having an inclinededge along which the cutting edge of said knife moves while cutting a slice from the loaf, the inner face of said ledger plate being grooved lengthwise from its inclined edge to provide ridges adapted to press into theadvancing loafand hold it down on said =table, said knife rotating in a direction to move the lower edge of said knife against said ledger'plate.

2. In a bread slicing machine, the combination with a helical knife, of means .for rotating said knife, mechanism for advancing a loaf continuouslybelow the axis of said knife and across its path, a stationary ledger pla'te arranged to engage one side of the loaf and oppose the side thrust thereon while it 'is being slicedand having an inclined edge along whi'ch the cutting edge of said knife moves while cutting a slice from the loaf, and a rotary cage adjacent said ledger plate and having circumferentially spaced upright bars which back up the portion of the loaf projecting beyond said inclined edge while the'loaf is being sliced.

3. In a bread slicing machine, the combination with a helical knife, of means for rotating said knife, a table beneath said knife, mechanism for continuously advancing a loaf lengthwise on said table and across the path of said knife, a guide on said table arranged to bear against one side of the advancing loaf, a. stationary ledger plate arranged to engage the other side of said loaf and oppose the side thrust thereon and having an inclined edge along which the cutting edge of said knife moves while cutting a slice from the loaf, and a rotary cage adjacent said ledger plate and having circumferentially spaced upright bars which back up the portion of the loaf projecting beyond said inclined edge while the loaf is being sliced.

4. In a bread slicing machine, the combination with a helical knife having a vclute cutting edge, of means for rotating said knife, a table beneath said knife, mechanism for continuously advancing loaves lengthwise on said table and across the path of said knife, and a device for delivering loaves into the range of action of said mechanism, said mechanism including a pair of driven sprockets, a pair of idler sprockets, and a pair of chains running over said sprockets and each provided with flights rigidly connected thereto, each flight on one chain being disposed to clamp a loaf endwise against an adjacent flight on the other chain, and said device including a traveling chain disposed above said table and provided with an arm 'pivotally mounted thereon, a pusher on said arm adapted to engage the end of a loaf on said table and push it into the path of said flights, a stationary horizontal track, a roller on said arm adapted to enter said track to turn said pusher into vertical position to engage a loaf on the table, and a stationary guide surface arranged beyond said track to engage said roller to turn said pusher upwardly and thereby cause it to clear the loaf being pushed.

5. In a bread slicing machine, the combination with a helical knife having a volute cutting edge, of means for rotating said knife, a table beneath said knife, mechanism for continuously advancing loaves lengthwise on said table and across the path of said knife, a device for delivering loaves into the range of action of said mechanism, while the same are beingcontinuously advanced and a device for ejecting the sliced loaves from said mechanism, said ejecting device including a slidable shaft parallel tothe path of the sliced loaves, and a sprocket splined to said shaft, a pair of arms fast to said shaft, and a pusher carried by said shaft.

6. The combination with a table, of mechanism for continuously advancing loaves lengthwise on said table, a device for delivering loaves into the range ofv action of said mechanism, and a device for ejecting the loaves from said mechanism while the same are being continuously advanced, said ejecting device including a slidable shaft parallel to the path of the sliced loaves, and a pusher carried by said shaft.

'7. The combination with a table, of mechanism 1 for continuously advancing loaves of bread endwise along said table, slicing means-including a knife and means for imparting movement to said knife to cut across the path of the loaves and at the same time follow their endwise movement, and means for delivering loaves into the range of action of said mechanism, said mechanism including sprockets, endless chain means passing over said sprockets provided with flights disposed to clamp a loaf endwise against an adjacent flight, co-operating flights being arranged to separate as a result of passage over one of said sprockets, and said device including a pusher adapted to engage a loaf and push it into the path of said flights while one of said flights is separated from the adjacent co-operating flight. 1

8. In a bread slicing machine, the combination with a helical knife having a volute cutting edge,

of means for rotating said knife, a table beneath said knife, mechanism for continuously advancing loaves lengthwise on said table and across the path of said knife, said mechanism being adapted to individualize the loaves, and a device for ejecting the sliced loaves from said mechanism while 9. In a bread slicing machine, the combination with a helical knife having a volutecutting edge, of means for rotating said knife, a table beneath said knife, mechanism for continuously advancing loaves lengthwise on said table and across the,

path of said knife in positively gripped individualized disposition, a device for delivering loaves into the range of acton of said mechanism, and a device for ejecting the sliced loaves, each as a unit, from said mechanism, while the collective slices are being continuously advanced in positively gripped assembly at right angles to the axis of rotation of the slicer.

THORMOD JENSEN. ANTON VAN VEEN. 

